JERUSALEM (AP) — The Israeli army said it launched an offensive operation early Tuesday against the Gaza Strip to quell rocket attacks, and a Palestinian official said Israeli airstrikes injured at least nine Palestinians. The Israeli airstrikes come after Gaza militants fired dozens of rockets at southern Israel on Monday, setting off air raid sirens and forcing hundreds of thousands of Israelis to stay indoors. A Twitter statement from the Israeli army said the offensive, dubbed "Operation Protective Edge," is intended to "stop the terror Israel's citizens face on a daily basis." The latest violence came as Israel pressed forward with its investigation of six Jewish youths suspected of abducting and killing a Palestinian teenager, and Israeli leaders sought to calm an emotional debate over whether the country's politically charged atmosphere led to the gruesome crime. There is a potential of deterioration due to their death. [...] the IDF has to continue to reinforce capabilities in the south, with the potential that things could escalate further, he said. Israeli security officials had said late Monday that Israel was leaning against a massive operation and would likely increase the pressure gradually with stronger and more numerous retaliatory attacks. Israeli officials Sunday announced the arrests of six Jewish youths in the killings - ruling out earlier theories that criminal activity or personal reasons might have been a factor. Abu Khdeir's death triggered several days of violent protests in Arab areas of Jerusalem and northern Israel as Palestinians accused Israeli extremists of killing the boy to avenge the earlier deaths of the Israeli teens. [...] Monday, Israeli police said a border policeman had been temporarily suspended from special operations and transferred to a different position until the completion of an investigation into the apparent police beating of Tariq Abu Khdeir, a Palestinian-American teenage cousin of the murdered Palestinian youth.